Long-Term System Monitoring

It is important not only to "spot-check" system performance with the
tools mentioned above, but to collect longer-term performance histories so
you can detect trends. If nothing else, a baseline record of a system performing
well will help you figure out what has changed if the system starts behaving
poorly. Enable the system activity reporting package by doing the following:

Edit the file /etc/init.d/perf and remove
the # comment characters from the lines near the end of
the file. For Solaris 10, run the following command:

svcadm
enable system/sar

Run the command crontab -e sys and remove the # comment
characters from the lines with the sa1 and sa2 commands.
You can adjust how often the commands run and at what times of day depending
on your site's activity profile. See the crontab man page
for an explanation of the format of this file.

This command causes
the system to store performance data in files in the /var/adm/sa directory,
where by default they are retained for one month. You can then use the sar command to examine the statistics for time periods of interest.